A common type of drainable urostomy pouch comprises a drainage tap or valve arrangement at its lower end, through which collected urine may be emptied. However, the tap or valve arrangement represents significant additional manufacturing inconvenience and cost, making the pouch more expensive to produce. The tap or valve components have to be molded separately from the pouch, and then fastened to the pouch. Often, a tap comprises plural components that cannot be pre-assembled, requiring assembly to be completed after attachment to the pouch. The integrity of the pouch depends on the tap or valve arrangement, and it is often not possible to quality-test a tap or valve prior to installation on the pouch.
U.S. Pat. No. 6,419,664 describes a drainable urostomy pouch comprising an elongated discharge portion provided by an extension of the pouch walls. The discharge portion is foldable into a closed condition which is said to seal the discharge portion. The discharge portion has a relatively narrow internal drain passage, the width of which is less than 60% of the external width of the discharge portion. The drain passage has a generally fluted shape tapering smoothly to a narrow portion within the discharge portion. When the discharge portion is folded to its closed condition, the drain passage is collapsed to seal the discharge portion. However, the drain passage is narrow, and may stick in its collapsed state (so-called pancaking) when the discharge portion is unfolded. U.S. Pat. No. 6,419,664 teaches permanently sealing a tube in the discharge portion to expand the drain passage when the discharge portion is unfolded. However, such a tube inevitably obstructs tight folding of the discharge portion when in its closed condition, possibly reducing the integrity of the seal and creating excessive bulging when a compact folded shape would be far more desirable to the wearer.
U.S. Publication No. 2004-0049837-A1 discloses a more refined drainable urostomy pouch also comprising a foldable elongated discharge portion formed as an extension of the pouch walls. Deformable bias strips provided at the distal end of the discharge portion enable the degree of distention of the discharge outlet to be manually controlled by the user, to thereby control the rate of flow of the liquid contents during emptying. The content of U.S. Publication No. 2004-0049837-A1 is incorporated herein by reference.